I have received some additional information from van in following the supplied programme for 6 - 8 weeks which will be a helpful guide for me. Shelby has been more settled the last day or so with less scratching, licking and scooting so a good sign and I hope it continues. Unfortunately potatoes are not good with her but orange sweet potato has been excellent. When I take her to the vet for her yearly check up soon I will ask about blood testing to check her lipids etc
I'm quite sure that part of the issue is garden related with grass, plants and will enquire also about testing for this.
Kalacreek knowing that schnauzers are prone to pancreatitis and she has always been sensitive to fat I try to keep the fat level in her diet low which is a problem when some fat is needed to assist with skin issues. What a huge learning curve. If nothing else I want to sort it for her health and comfort.